This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The glycopeptide hormone (GPH) signaling pathways play essential roles in human health and development and are critical for normal physiological control and fertility. To gain a better understanding of the developmental functions of these pathways as well as to uncover the factors that modulate their signaling at the molecular level, we have undertaken studies in the model organism, C. elegans. Our studies have revealed roles for the C. elegans GPH-like receptor, FSHR-1, in regulating oocyte and sperm development, in promoting the maintenance of a robust germline stem cell population, and in controlling germ cell survival by inhibiting apoptosis. Our results therefore indicate a conserved role for GPH family receptors across species in controlling germline development and fertility. Our data also suggest a model whereby FSHR-1 signaling acts in parallel to the known sex determination pathway of C. elegans, via the soma, to control multiple aspects of germline development. Additional studies will shed further light on the molecular details of GPH receptor-mediated signaling in C. elegans, which based on the observed functional conservation of family members, is likely to provide novel insight into how these important signaling pathways are regulated in humans.